PR review feedback for threads - fix download loader, n. of threads render

[tomholub]

Thank you Ivan for getting it up to master!

I'll merge it but there will still be some fixes to do after:

• download percentage is not getting rendered anymore - I think
• with a very long subject, the number of messages in thread gets hidden because it's at the end

Originally posted by @tomholub in #657 (review)

[ivan-ushakov]

@tomholub

We keep number of messages in thread at sender's level

[ivan-ushakov]

It is still possible that number of people in thread is too big and in this case number of messages in thread will be hidden. Like this:

It is possible to solve with independent label for this number.

[tomholub]

You're right - it's the senders that can get too long. Yes - independent label would be great. Thanks!

[ivan-ushakov]

@tomholub
What do you think?